Foundry wash and process of manufacturing the same



Patented Dec. 2, 1924.

UNITED STATES EDWARD D. FROHMAN, 0F PITTSBURGH, PENNSYLVANIA.

FOUN'DRY WASH AND PROCESS 0] MANUFACTURING THE SAME.

No Drawing.

To all whom it may concern:

Be it known that I, EDWARD D. FROHMA'N, a citizen of the United States, and residing in the city of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented or discovered the new, useful, and Improved Foundry Wash and Process of Manufacturing the Same, of which the following is a specification.

My invention consists in a new and improved composition for forming washes used in foundries for coating sand cores and molds, and process for manufacturing same.

The purpose of such wash is to give the cores and molds a smooth, uniform surface, capable of standing up in the presence of the molten metal yet open and porous, and to prevent sand from adhering to the castmg.

According to the present practice, cores and molds to be used in casting brass, gray iron and malleable iron are treated with a wash having a basis of material non-fusible in the presence of the metal casting temperature, such as coke dust or silicious clay, silicates, plumbago, graphite, black lead or powdered soapstone. Or a combination of any two or more of the same is used as the basis. Such material or materials are supplied to the foundry in powdered form, and there mixed with a binder such as molasses, dextrine or sulphite pitch. The mixed materials are then by the addition of water re duced to a'solution of the consistency of paint which is then painted on the surface of the cores or molds, or the cores may be dipped in the solution.

is commonly known as scabs or blows.

If too little bindtr is used in the solution the wash material is swept by the molten metal, causing dirt spots in the castings Application filed November 30, 1923. Serial No. 677,889.

which render them unfit for commercial use.

To overcome these difficulties, and to satisfactorily meet the requirements of the situation I have invented a new and improved core and mold wash, and process of manufacturing the same.

Again, to enable a satisfactory wash solution to be prepared on the foundry floor, I have invented a new and improved wash compound which is supplied in a prepared form of a substantial colloidal putty-like consistency to the foundries, and may be mixed with water on the foundry floor to form the paint-like wash.

In the practice of my invention I take any one, or a combination of two or more, of the base wash materials mentioned aboveand redce them to a finely divided and dry state. I then mix them with a suitable binding material, such as molasses, dextrine, sulphite pitch or glue, and a small quantity of suitable organic oil, such as vegetable oils having a binding value, as rosin oil, core oil, corn oil, linseed oil or fish oil. The propor tions used are about one hundred parts in weight of base material, not more than five parts of the binding material and not more than a like quantity of the oil. The proportions of binder and oil vary with the character of sand used in making the molds or cores. An open sand would require a greater proportion of binding material and oil'than a close sand. I prefer to use a vegetable oil owing to its superior binding qulalities a compared with mineral organic 01 s.

The process which I prefer to use in preparing my composition is to first reduce the base materials by grinding to a finely divided powder. The oil is then added to the base material and thoroughly mixed in a mixing pan or machine to form a colloidal compound; and sufficient water is then added, and the materials are thoroughly mixed until the composition has a consistency of putty.

This putty-like composition is sold to the foundries,and when a wash is to be used a sufficient quantity of the composition is dissolved and thoroughly mixed in sufficient water to produce a solution of paint-likeconsistency, which is thenpainted over the surfaces of the cores or molds; or in the case of small cores .the same may be dipped in the solution.

The presence of the oil as an ingredient in the colloidal composition results in a smoothness and freedom from lumps, which is practically unobtaina-ble in the present practice of entirely preparing the wash on the foundry floor.

A wash solution formed with the use of my composition is in the nature of an emulsion which maintains the various ingredients in perfect suspension until used. The washes prepared by the present practice are not permanent combinations, but the ingredients. tend to precipitate or settle to the bottom of the bucket or container where they harden. Where my improved wash material is used the combination is substantially permanent and may stand for weeks without precipitation and without impairment of its virtue, additional water being added from time to time to compensate for evaporation.

Under the old practice, the efficacy of the wash prepared on the foundry floor depended largely on the skill of the workman. \Vith the use of my composition no skill is required, since enough of my composition is simply added to the water and thoroughly stirred up therein to give the consistency which the Workman knows is necessary.

What I desire to claim is 1. A wash compound for foundry cores and molds which is composed of a finely divided base material non-fusible in the presence of the metal casting temperatures and having carboniferous characteristics, a binding material, and an organic oil.

2. A wash compound for foundry cores and molds which is composed of a. finely divided base material non-fusible in the presence of the metal casting temperatures and having carboniferous characteristics, a binding material, and a vegetable oil.

3. A wash compound for foundry coresand molds which consists of a finely divided base material non-fusible in the presence of the metal casting temperatures and having carboniferous characteristics, a binding material and an organic oil together with sufficient water to form a colloidal and puttylike substance miscible with water.

4. A wash compound for foundry cores and molds which consists of a finely divided base material non-fusible in the presence of the metal casting temperatures and having carboniferous characteristics, a binding material and a vegetable oil together with sufficient water to form a colloidal and putty like substance miscible with water.

5. A wash compound for foundry cores and molds which consists of a finely divided base material non-fusible in the presence of metal casting temperatures said ma terial having carboniferous characteristics, a binding material and an organic oil, the proportions being about one hundred parts in weight of the base material, not more than five of the binding material and about like quantity of the oil.

6. The process of manufacturing a wash composition for foundry cores and molds which consists in first reducing to powder a base material non-fusible in the presence of metal casting temperatures, said material having carboniferous characteristics, then thoroughly mixing therewith an organic oil and finall adding water to form a colloidal compound of the consistency of putty.

Signed at Pittsburgh, this 28th day of November, 1923.

EDWARD D. FROHMAN. 

